Vegetative compatibility and RFLP analysis of colletotrichum destructivum isolates from alfalfa and red clover

Abstract

A total of 17 isolates of Colletofrichum from alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) plants with anthracnose symptoms were collected from 11 districts in Serbia during 2005-2010 and tested for variability in vegetative compatibility groups (VCGs) and restriction fragment length polymorphisms (RFLP). Nitrate non utilising (nit) mutants were isolated from each of investigated C. desfructivum isolates by selecting chlorate -resistant sectors on medium with chlorate. The isolates were grouped in five VCGs while one isolate was self -incompatible. No relationship was found between VCGs and geographical origin of the isolates. Restriction Fragment Length Polymorphism (RFLP) analysis of a 900 bp intron of the glutamine synthetase (GS) gene revealed a unique polymorphic profile of C. destructivum isolates, distinct from the profiles of other Colletofrichum species. An identical profile was produced for all C. desfructivum isolates, regardless of their host and geographical origin. PCR-RFLP failed to detect some the Serbian C. desfructivum isolates.